1. Field of the Invention
The present invention relates to an exhaust apparatus.
2. Description of the Related Art
As disclosed in, for example, Japanese Laid-Open Patent Application Publication No. 2011-247161, an exhaust apparatus mounted on a motorcycle or the like includes: an exhaust pipe connected to a downstream side of an exhaust port of an engine; an inner tube whose upstream end portion is connected to the exhaust pipe and whose peripheral wall portion is provided with a plurality of opening portions; an outer tube accommodating the inner tube so as to cover an outer periphery of the inner tube; a sound absorbing material arranged in a space located between the inner tube and the outer tube; a tail pipe connected to a downstream end portion of the inner tube; and an end cone covering the tail pipe.
While the engine is operating, an exhaust gas flows through an exhaust passage, constituted by the insides of the exhaust pipe, the inner tube, and the tail pipe, to be discharged outside. At this time, the exhaust gas flows through the opening portions of the peripheral wall portion of the inner tube to flow through the inside of the sound absorbing material. Thus, exhaust sound is reduced. With this, the exhaust apparatus achieves a silencing effect of the exhaust sound.
According to the exhaust apparatus configured as above, the exhaust gas is introduced to the sound absorbing material arranged in an internal space located between the outer tube and the inner tube. With this, a certain degree of silencing effect of the exhaust sound is obtained. However, a higher silencing effect is desired. In addition to the high silencing effect, satisfactorily maintaining an exhaust efficiency of the exhaust gas in the exhaust apparatus is also desired.
The present invention was made in light of the above problems, and an object of the present invention is to provide an exhaust apparatus having a relatively simple configuration but capable of achieving an excellent silencing effect while maintaining a satisfactory exhaust efficiency of an exhaust gas.